Yesterday, as the massive arm of the 1,600 - ton large - sized floating crane“Yingshang No. 1”slowly stretched out, the first steel box girder of the main section of the Xiangshan Bay Cross -sea Bridge on the suburban railway was smoothly inserted into the designated position. This is another crucial milestone since the successful erection of the first precast box girder on the approach section of the bridge in November 2024，which marks the full - scale launch of the steel box girder erection on the main section of the bridge, laying a solid foundation for the subsequent closure of the main bridge.

The Xiangshan Bay Cross - sea Bridge on the urban railway has a total length of 8.26 kilometers. The main section of the bridge is 1.376 kilometers long and consists of 95 segments. The steel box girder erected this time is located at the No. 68 main pier, with a length of 11 meters and a weight of 194 tons, which is equivalent to the weight of more than 30 adult African elephants. To meet the high - standard alignment requirements for wind and earthquake resistance of the cross - sea bridge, Ningbo Rail Transit innovatively adopted an integrated process of transport ship positioning combined with floating crane hoisting. It also incorporated the Beidou satellite positioning system and intelligent sensing technology to firmly control the docking accuracy of the steel girders within the millimeter - level range. “Building ‘blocks’at sea is ten times more difficult than on land!" Xu Xiaokai, the owner's representative, introduced. ”With the help of the ‘Beidou positioning and intelligent anti - shaket’echnology, the error of the weld seam is less than the thickness of a human hair (3 millimeters).”

It is reported that the main piers of the bridge are adjacent to the main shipping channel of Xiangshan Bay, resulting in a high frequency of construction escort operations.To this end, Ningbo Rail Transit has jointly tailored a Smart + water construction safety guarantee model with Ningbo Maritime Department. It utilizes digital platforms such as Smart Maritime and CCTV, and eliminates navigation - obstruction risks through the combination of on - site warning and remote monitoring to ensure the safe and smooth progress of the project construction.